CHARACTERIZATION OF RED PIGMENTS EXTRACTED FROM RED BEET (BETA VULGARIS, L.) AND ITS POTENTIAL USES AS ANTIOXIDANT AND NATURAL FOOD COLORANTS

Abstract

Red pigments extracted from red beet (Beta vulgaris,L.) were identified for major constituents by using HPLC, these pigments were used as alternative natural red colorants in some processed foods, i.e. jelly and ice sherbets. Also, the effect of using red beet extract as natural antioxidant on corn oil was studied. The results showed that red beet had 380 mg betalain /100g on fresh weight. The major constituents " of red beet pigments were betalain and isobetalain by analyzing with HPLC. The best carriers for red beet pigments were dextrin followed by soluble starch, lactose and glucose, respectively. On the other hand, color and higher pigment stability of betalain pigments extracted from red beet were at pH ranged between 3.0 to 7.0 and temperature ranged between 40.0 to 50.0C. Meanwhile, the degradation of red pigments were 82.0% of the total pigments after 180 min at 90C. Antioxidant activity of red beet extracts were assessed by measuring peroxide value in corn oil during 7 days at 60C corn oil contained 1000 ppm was able to lower the peroxide value than using 200 ppm synthetic antioxidant butylated hydroxyl toluene (BHT). Analysis of variance for sensory evaluation of prepared jelly and ice sherbets indicated that, jelly samples containing 0.30% and ice sherbets containing 0.20% red beet pigments were given the highest scores of color, taste and overall acceptability similar with synthetic color carmine.